Amese salts of penicillin g



AMINE SALTS OF PENICILLIN- G William H. Edgerton, Huntington Woods, and Robert L.

Hull, Detroit, Mich., assignors to Parke, Davis & Company, Detroit, Mich., a corporation of Michigan No Drawing. AppIicationAugust-II, 1953, Serial No. 373,655

8 Claims. (Cl. 260-4391) This invention. relates to salts of penicillin G and to methods for-producing the same. More-particularly; the invention relates to N-phenalkyl-ubenzylphenethylaminesalts of penicillin G which have the formula man where n and R have the same significance as given above and HMis one equivalent ofa mineral acid; in an aqueous reaction medium. Some of the" water soluble salts" of penicillin G which can be used are sodium penicillinG, potassium penicillin G; calcium penicillin and. am monium penicillin G while suitable mineral acid salts of the N-phenalkyl-a-benzylphenethylaminecompound are the hydrochloride, hydrobromide, sulfate, hydro-iodide, phosphate, sulfamate and the like. As a reaction medium water or an aqueous solution' containing a water-miscible organic solvent can be used. Some of the water miscible organic solvents which can be employed for this purpose are methanol, ethanol, isopropanol, acetone, N,N-di methylacetamide, N,N-dirnethylformamide, dioxane and the monomethyl ether ofethylene'glycol. In carrying out the process the" temperature of the'reaction mixture is kept below 40 C-.. to minimize the decomposition ofthe penicillin: G'reactant and the final product. The pre-' ferred reaction temperature: is in the neighborhood of 15 to 30 C. Approximately: equivalent, quantitiesof; the two reactants are preferably? employed in carryingtthe 2,735,848 Patented Feb. 21, 1956 2. process although, if desired, a small excess of either of the reactants can be used.

The N-phenalkyl-a-benzylphenethylamine salts of penicillin G of the invention canalsojbe produced by reacting benzylpenicillinic acid (the free acid. of penicillin G) with a the free base, of an N phenalkyl-a-benzylphenethylamine of formula where n and R have the same significance as given. above; in substantially anhydrous organic solvent such as ether, benzene, chloroform, xylene, ethylene dichloride and the like. The temperature during the reaction is kept below 40 C. and preferably between about 0 and 20 C. Approximately equivalent quantities of the two reactants are preferably employed but, if desired, a slight excess of either reactant can be used.

The products of the invention are only very slightly soluble in water and are of particular value in the instances where it is desirableto administer penicillin by the oral route. These products upon oral administration produce extremely high blood levels of penicillin G which persist for long periods oftiine. The products can be admixed. with inert diluents and pressed into tablets or filled into capsules for convenient administration. They may also be incorporated into emulsions or suspensions for administration-by: either the oral or parenteral routes. The-usual oral dosage for humans of the penicillin. salts of the invention in the treatment of. most conditions is in the: neighborhood'of-250 to. 400- mg. twoto four times per day.

Theinvention is; illustrated by the following: examples.

Example 1 A solution containing 1 g. of potassium penicillin G assaying. 1578 Oxford units per mg. in 20 to 40 ml. of water is added to asolution: containing 0.91 g, of N- benzyl-a-benzylphenethylamine hydrochloride in 20 ml. of N,N-dimethylacetamide at room temperature. The reaction mixture is cooled and the desired N-benzyl-abenzylphenethylamine salt of penicillin G collected and washed with water; M. P. 119-2l C. This salt which is soluble in water to the extent of 0.076% at 25 C. contains by assay about 930 Oxford units of penicillin per mg. The formula of this-compound is If desired, an'equivalent amount of either sodium penicillin G or calcium penicillin G can besubstituted for the potassium penicillin G used in the above procedure. Also, if desired, an equivalent amount of either N-benzyltat-benzylphenethylamine hydrobromide or N-benzyl-abenzylphenethylamine sulfate can be substituted for the N-benzyl-a-benzylphenethylamine hydrochloride used in the above procedure.

Example 2 NH-O o-omQ Example 3 A solution containing 1 g. of potassium penicillin G assaying 1578 Oxford units per mg. in 25 ml. of water is added to a solution containing 1 g. of N-p-ethoxybenzyltat-benzylphenethylamine hydrochloride in 20 ml. of N,N- dimethylacetamide at room temperature. The reaction mixture is cooled and the desired N-p-ethoxybenzyl-otbenzylphenethylamine salt of penicillin G collected and washed with water; M. P. 129-330 C. This salt which is soluble in water to the extent of 0.047% at 25 C. contains by assay about 865 Oxford units of penicillin per mg. The formula of this compound is on3 HzC O onion:

Example 4 A solution containing 1 g. of potassium penicillin G assaying 1578 Oxford units per mg. in 25 ml. of water is added slowly with stirring to a solution containing 1.1 g. of N-p-isopropoxybenzyl-u-benzylphenethylamine hydrochloride in 20 ml. of N,N-dimet hylacetamide at room temperature. The reaction mixture is cooled and the desired N p isopropoxybenzyl-a-benzylphenethylamine salt of penicillin G collected and washed with water; M. P. 142-43 C. This salt which is soluble in Water to an extent of 0.033% at 25 C. contains by assay about 845 Oxford units of penicillin per mg. The formula of this compound is A solution containing 1 g. of potassium penicillin G assaying 1578 Oxford units per mg. in 20 ml. of water is added slowly with stirring to a solution containing 1.2 g. of N-p-v-chloropropoxybenzyl a benzylphenethylamine hydrochloride in 20 ml. of N,N-dimethylacetamide at room temperature. The reaction mixture is cooled and the desired N-p-' -chloropropoxybenzyl-a-benzylphenethylamine salt of penicillin G collected and washed with water; M. P. 12830 C. This salt which is soluble in water to the extent of 0.021% at 25 C. contains by assay about 870 Oxford units of penicillin per mg. The formula of this compound is CH: om-O-oomcmomm o--oH-o 0 6-1311,

Example 6 Example 7 A solution containing 1 g. of potassium penicillin G assaying 1578 Oxford units per mg. in 25 ml. of water is added slowly with stirring to a solution containing 1.1 g. of N-p-n-amyloxybenzyl-tit-benzylphenethylamine hydrochloride in 20 ml. of N,N-dimethylacetamide at room temperature. The reaction mixture is cooled and the desired Nep-n-amyloxybenzyl o: -"benzylphenethylamine salt of penicillin G collected and washed with Water; MQP. 1343'5 C. 'Thissalt'whichi-is soluble in' waterto the extentof0.01'2%-at 25C. contains by-assay about 815 Oxford units of penicillin per mg. The formula of this compound is CH; /oH,-C -oomomomomom c ---o H-0 0 o-rim A solution containing 1 g. of potassium penicillin G assaying 1578 Oxford units per mg. in 25 ml. of water is added slowly with stirring to a solution containing.

,1 g. of 'N-p-isopropylbenzyl-u-benzylphenethylamine hydrochloride in 20 ml. of N,N-dime'thylacetamide at room temperature. "The reaction mixture is cooled .and'the Idesired N-p-isopropylbenzyl-tx-benzylphenethylamine salt of penicillin G collected and washed with water; 'M. .P. l37-38 C. This salt which is soluble in water to the extent of 0.022% at 25 C. contains by assay about 885 Oxford units of penicillin per mg. The formula of this compound is cal IHHQ Arsolution containingl g. of potassium penicillin-G assaying 1578 Oxford unitsper mg. in 150 ml. of water is added slowly with stirring to a solution containing 2 'g. of 'N-'y-p'henylpropylu benzylphenethylamine hydrochloride and 25 mlsof N,N-dimethylacetamide at room temperature. The reaction mixture is cooled and the-desired N-v-phenylpropyl-a-benzylphenethylamine salt --of penicillin G collected and washed with water; M, "P. 117-19 C. This salt which is soluble inwater-to"the extent of 0.02% at 25 C. contains -by assay about 875 Oxford-units of penicillin per mg. The formula of this compound is on, cmo-mcm-Q Nil- O o-omG Example 10 mula of this compound is onto-0%: moment -o on-o.o (x-ring lHMH Example 11 A solution containing 1 g. of potassium penicillin G assaying 1578 Oxfordunits per mg. -in ml. of water is added slowly with stirring to a solution containing 1.3 g. of N-p-n-decyloxybenzyl-ot-benzylphenethylamine hydrochloride in 20 ml. of N,N-dimethylacetamide at room temperature. The reaction mixture is cooled and the desired N-p-n-decyloxybenzyl-a-benzylphenethylamine salt of penicillin G collected and washed with water; M. P. 14244 C. This salt which is soluble in water to the extentof 0.012% at 25 C. contains by assayahout 740 Oxford units 'of'penicillin per mg. The formula of this l IH -C O-OHr-O Example 12 A solution containing 1 g. of potassium penicillin G assaying 1578 Oxford/units 'per mg. in 20 ml. of water 7 is added slowly With stirringto a solution containing 1 g. of N-p-chlorobenzyl-a-benzylphenethylamine hydrochloride in 20 ml. of -N',N-dimethylacetamide at room temperature. The yreaction mixture is cooled and-the :desired:N-p-chloroben yl-u-benzylphenethylamine salt of penicillin G collected and washed with water; M. P. .126I2 8 C. Thissalt which is soluble in water to the extent :of 0.065% at 25 C. contains by assay about '8'80' Oxfordunits of penicillin per mg. The formula of *thiscompoundis corr o o-rirn S\ N\ (EH:

Example 13 NE-C o-om-O Example 14 A solution containing 1 g. of potassium penicillin G assaying 1578 Oxford units per mg. in 20 ml. of water is added to a solution containing 1.1 g. of N-sec.-butoxybenzyl-a-benzylphenethylamine hydrochloride in 20 ml. of N,N-dimethylacetamide at room temperature. The reaction mixture is cooled and the desired N-sec.-butoxybenzyl-ot-benzylphenethylamine salt of penicillin G is collected and washed with water; M. P. 142-43 C. This salt which is soluble in water to the extent of 0.026% at 25 C. contains by assay about 820 Oxford units of penicillin per mg. The formula of this compound is Example 15 A solution containing 2 g. of potassium penicillin G assaying 1578 Oxford units per mg. in 40 ml. of water is added to a solution containing 2.4 g. of N-p-benzyloxybenzyl-u-benzylphenethylamine hydrochloride in 40 ml. of N,N-dimethylacetamide at room temperature. The reaction mixture is cooled and the desired N-p-benzyloxybenzyl-ut-benzylphenethylamine salt of penicillin G is 8 collected and washed with water; M. P. 139-4l C. This salt which is soluble in water to the extent of 0.009% at 25 C. contains by assay about 790 Oxford units of penicillin per mg. The formula of this compound is Example 16 A solution containing 1 g. of potassium penicillin G assaying 1578 Oxford units per mg. in 25 ml. of water is added slowly with stirring to a solution containing 1.1 g. of N-p-isoamyloxybenzyl-ot-benzylphenethylamine hydrochloride in 20 ml. of N,N-dimethylacetamide at room temperature. The reaction mixture is cooled and the desired N-p-isoamyloxybenzyl-a-benzylphenethylamine salt of penicillin G collected and washed with water; M. P. 134-35 C. This salt which is soluble in water to the extent of 0.019% at 25 C. contains by assay about 800 Oxford units of penicillin per mg. The formula of this compound is CHOO-CHzCHaC Example 17 A solution containing 0.95 g. of sodium penicillin G assaying 1650 Oxford units per. mg. in 20 ml. of water is added slowly with stirring to a solution containing 1.1 g. of N-p-n-butoxybenzyl-a-benzylphenethylamine hydrochloride in 20 ml. of N,N-dimethylacetamide at room temperature. The reaction mixture is cooled and the desired N-p-n-butoxybenzyl-a-benzylphenethylamine salt of penicillin G collected and washed with water; M. P. l3234 C. This product is identical in all respects to the product produced by the procedure described in Example 6.

The N-phenalkyl-a-benzylphenethylamines and their mineral acid salts used as starting materials in the practice of the invention can be prepared by the methods described and claimed in our copending application Serial No. 373,654, filed under even date herewith. One of these methods involves reacting a compound of formula with a compounds of formula where n and R have the same significance as given above and X is halogen atom or a primary amino group and Z is a primary amino group when X is a halogen atom and Z is a halogen atom when X is a primary amino group. The reaction is preferably carried out at a temperature between 80 and 110 C. using approximately equivalent amounts of the two reactants in a solvent such as a lower aliphatic acohol, benzene, toluene, xylene or the like. In this instance the product is the hydrohalide salt of the desired amine while if two equivalents of the amine starting material are used the product is the free base of the desired N-phenalkyl-a-benzylphenethylamine.

Another method for producing the N-phenalkyl-abenzylphenethylamines comprises reacting ot-benzylphenethylamine with an aldehyde of formula and subjecting the Schiii base compound so produced to catalytic hydrogenation; where R has the same signiiicance as given above and Y represents a direct bond from the carbonyl group of the phenyl ring, an alkylene group containing 1 or 2 carbon atoms or a vinylene radical. The first step of the process is preferably carried out in a substantially anhydrous organic solvent such as a lower aliphatic alcohol, benzene, toluene, Xylene and the like at a temperature between 60 and 100 C. The catalytic hydrogenation is preferably carried out in the same solvent as used in the first step and in the presence of a noble metal catalyst. The preferred hydrogen pressure for the reduction is between two to four atmospheres while the preferred temperature is between 25 and 60 C.

What we claim is:

1. A N-phenalkyl-a-benzylphenethylamine salt of penicillin G of formula (emu-OR NH-C 043110 where n is 1 to 3 and R is a member of the class consisting of hydrogen atom, a halogen atom, an alkoxy group,

an a lower alkyl group, a monohalo lower alkoxy group and a benzyloxy group.

2. A N-phenalkyl-u-benzylphenethylamine salt of peni- Cllllll G of fOI II .113,

C H O-Blk0 0 xy -on c oo-rirn 0 of, l

N Hz

cillin G of formula CO on rim-o 0-0 Ian-Q where n is 1 to 3.

8. The N-q-phenylpropyl-u-benzylphenethylamine salt of penicillin G.

References Cited in the file of this patent UNITED STATES PATENTS Buckwalter Feb. 12, 1952 Cheney Feb .12, 1952 

1. A N-PHENALKYL-A-BENZYPHENTHYLAMINE SALT OF PENICILLIN G OF FORMULA 